Comparative Proteomic and Phospho-proteomic Analysis of Mouse Placentas Generated via In Vivo and In Vitro Fertilization

Offspring conceived by assisted reproductive technologies (ART) have increased risk of suffering from gestational complications, and placental dysfunction is related with the adverse outcomes. Studies have revealed that abnormal or adaptive changes can occur in ART placentas, but the potential reasons are not fully understood. Hereby, we tried to use proteomics and phospho-proteomics to find the underlying mechanisms responsible for the changes of ART placentas. Liquid chromatography–tandem mass spectrometry was utilized to perform proteome and phospho-proteome detection on mouse placentas. The differential expressed proteins (DEPs) or phospho-proteins (DEPPs) were analyzed based on subcellular localization, functional classification, and enrichment. Western blot was used to verify the DEPs (Afadin, ZO-1, Ace2, Agt, Slc7a5, and Slc38a10) and measure mTOR signaling activities (mTOR, Rps6, and 4Ebp1). The data showed that 161 DEPs and 304 DEPPs were found in proteome and phospho-proteome, respectively. Multiple biological processes were enriched based on those DEPs and DEPPs, and renin–angiotensin system, cell junction, and PI3K-Akt pathway were investigated. By protein expression identification, two key proteins associated with renin–angiotensin system (Ace2 and Agt) were down-regulated, and the levels of Afadin and ZO-1 (related with cell junction) as well as Slc38a10 were increased in IVF placentas. In addition, mTOR downstream activities were increased as shown by p-Rps6 and p-4Ebp1 in IVF placentas. In conclusion, IVF leads to the changes of cell junction, renin–angiotensin system, amino acid transport, and increased mTOR signaling in mouse placentas, which may be associated with the altered structure and function of IVF placentas.